Polyamide polymerization production process and equipment for same

Abstract

The invention relates to a polyamide polymerization production process and equipment for the same. The polyamide polymerization production process comprises the following steps of: carrying out prepolymerization on melted caprolactam, titanium dioxide, benzoic acid, and the like at a high temperature, and then carrying out front polymerization and post polymerization; pelleting; pre-extracting; extracting; pre-drying; and drying to obtain a product. The production equipment comprises a hexanolactam melting system, a preparation system, a feed system, a high-temperature prepolymerization device, a front polymerization tower, a rear polymerization tower, a pelleting system, a pre-extraction tower, an extraction tower, a pre-drying tower, a drying tower, and the like. According to the invention, static state flow guide spiral mixer assemblies are additionally arranged in the extraction tower and the lower sections of each row of tubes of the high-temperature prepolymerization device, the front polymerization tower and the post polymerization tower; the polyamide hydrolyzing ring opening and dewatering are more uniform and sufficient and faster; the front polyaddition reaction is sufficient and stable; the rear polycondensation stage is more uniform and stable in molecular distribution; the extraction tower more sufficiently and stably extracts a caprolactam monomer; the pre-drying tower can be used for removing the surface moisture of a slice; the drying tower dries combined water; a recovery system can be used for recovering an oligomer and extracts the caprolactam monomer contained in water.

Description

technical field [0001] The invention relates to a polyamide polymerization production process and equipment used therein. Background technique [0002] At present, the polyamide nylon 6 slice polymerization process and equipment used in my country mainly refer to foreign imported equipment and processes, which mainly include Jima, Inventa, Agafel, PE, Noy and so on. The imported equipment and process are basically one-stage or two-stage polymerization. In addition to requiring a large amount of foreign exchange investment, there are also many unreasonable designs in the process equipment, such as for high-end civilian high-speed spinning chips, especially for high-end fine denier spinning. The problem of wire slicing will be more obvious. The produced slices have poor stability, uneven molecular distribution, severe viscose particles, and difficult controllability. . [0003] The imported foreign process equipment is composed of caprolactam melting system, titanium dioxide...

AI Technical Summary

Problems solved by technology

[0006] 1. The function design of the equipment section in the polyamide reaction stage is unreasonable, and the function of the reaction area is not clear, resulting in confusion in the reaction equilibrium time;

[0007] 2. The molecular distribution of the polymerization reaction is too wide, the molecular weight changes greatly, and the stability is poor;

[0008] 3. There is vapor resistance boiling in the extraction system, there are dead angles and oxidation phenomena in the slice movement, and there is no way to extract oligomers;

[0009] 4. The drying temperature is too high, the slices are dried at high temperature, and the solid-phase viscosity of the slices is seriously increased

[0013] Although the above-mentioned patented technology has greatly improved the product quality, it still does not solve the most fundamental problem in the polyamide polymerization reaction, that is, it can be fully and uniformly mixed, stable, and free of dead ends in large-scale polymerization equipment with high temperature, high pressure and high viscosity. low temperature drying

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